Wait for Sandbox Email

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, non-destructive, open-world, and non-idempotent. The description adds genuinely new behavior: this call polls/blocks until a match arrives, auto-extracts 4-8 digit OTP codes and action links, and requires EMAILENS_API_KEY auth. It stops short of describing what happens on timeout or how results are shaped.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the core blocking behavior, then the value-add (OTP/link extraction), then the prerequisite. No filler; every sentence carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully signals what the agent gets back (OTP codes, action links) and flags the auth prerequisite. It omits timeout/failure semantics, which matters for a polling tool, but the schema covers the timeout parameter itself.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so sender, inboxId, subject, and timeoutSeconds are fully documented in the schema. The description adds no syntax, matching semantics, or default/max hints beyond what the schema already provides; baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource: 'Poll and wait for a matching incoming test email in the sandbox.' The blocking/polling nature distinguishes it from read-once siblings like sandbox_get_message, though no sibling is named explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is only implied by the phrase 'zero-regex test assertions' and the required API key, which suggest an end-to-end test flow. There is no explicit when-to-use, when-not-to-use, or routing to alternatives such as sandbox_list_messages for non-blocking checks.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.